I've worked at some of the "top tier" finance firms over the years.

It is absolutely astounding how much of them run on code that is:

- very reliable aka it almost never breaks/fails

- written in ways that makes you wonder what series of events led to such awful code

For example:

- A deployment system that used python to read and respond to raw HTTP requests. If you triggered a deployment, you had to leave the webpage open as the deployment code was in the HTTP serving code

- A workflow manager that had <1000 lines of code but commits from 38 different people as the ownership always got passed to whoever the newest, most junior person on the team was

- Python code written in Java OOP style where every function call had to be traced up and down through four levels of abstraction

I mention this only b/c the "LLMs write shitty code" isn't quite the insult/blocker that people think it is. Humans write TONS of awful but working code too.